Synaptinemal complex permits

Options

A. disjunction
B. the proper alignment of the homologous chromosomes
C. congression
D. all of the above

Answer

### Step-by-Step Solution:

1. **Understanding the Synaptonemal Complex**:
- The synaptonemal complex is a protein structure that forms between homologous chromosomes during the prophase I stage of meiosis, specifically during the zygotene phase.

2. **Formation of the Synaptonemal Complex**:
- It is composed of DNA and proteins and facilitates the pairing of homologous chromosomes. This pairing is crucial for genetic recombination.

3. **Function of the Synaptonemal Complex**:
- The primary function of the synaptonemal complex is to ensure the proper alignment of homologous chromosomes. This alignment is essential for the exchange of genetic material (crossing over) during meiosis.

4. **Evaluating the Options**:
- **Option A: Disjunction** - Disjunction refers to the separation of chromosomes. This does not occur during the formation of the synaptonemal complex, so this option is incorrect.
- **Option B: Congression** - Congression means the joining of two chromosomes. While the synaptonemal complex does involve the alignment of chromosomes, it does not merely refer to their joining, making this option incorrect as well.
- **Option C: Proper alignment of homologous chromosomes** - This option accurately describes the function of the synaptonemal complex, as it ensures that homologous chromosomes are aligned correctly for recombination.

5. **Conclusion**:
- The correct answer to the question "Synaptonemal complex permits" is the proper alignment of homologous chromosomes.